>>44060999BW: 7/10. There are quite a few amazing Pokemon here. Volcarona, Haxorus, and Bisharp are absolutely amazing. There are some stinkers, specifically the three monkeys and their evolutions. Aside from those, the dex overall is pretty solid!
XY: 6/10. A lot of the designs here go for a more weird tone. There are some amazing mons, such as Talonflame, Tyrantrum, and Noivern. There are some that really miss their mark, such as Delphox and Aromatisse. A good bunch of Pokemon, with some weird choices in there as well.
SM: 9/10. This gen has an amazing selection of Pokemon! Lycanroc, Lurantis, Golisopod, Tsareena, and a bunch of others! Along with the introduction of regional forms, this gen really hit their mark on good Pokemon! Aside from some weird choices, such as Bruxish and the Ultra Beasts being hit or miss, this has the best selection of nu-gen Pokemon!
SwSh: 4/10. The quality of Pokemon definitely took a nose dive here. There are still great mons here, such as Corviknight and Dragapult. However, a bunch of the other mons are really weird and forgettable. Not necessarily bad, but its not good either. Regional forms do return, but it feels more of a case of just having them than a case of making them adapt to their new environment, but that could just be me.